How To Analyze Imagery

You can analyze imagery in the browser by taking measurements, comparing imagery side by side, enhancing imagery, applying visualizations, and creating a timelapse. Measurement tools can be found on the map. All other analysis tools can be found in the toolbar on the right hand side.

Take Measurements

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You can measure the distance between two points, the area within a polygon or the bearing of a drawn line.

The measure tools are on the bottom right hand corner of the map, below the Draw an AOI button. If you float over this icon, you will see these available tools:

  • Note that when clicking on these tools to use them, the active tool that you are using turns teal. This will change depending on the active tool you are using at the time.

The first icon from the left (a compass icon) is the Measure Bearing tool, which allows you to measure the bearing between to points of your choice on the map. When you float your mouse over the map, you are prompted to Click on two points to calculate bearing.

Once you click on two points, the results are displayed on the map until you clear them (by clicking the trash bin icon). You can continue to create sets of two points and calculate their bearing, as needed.

  • Note: You can create multiple types of measures on the map. I.e. if you create a bearing measurement, and then choose to create an area measurement, both will continue to be visible on the map until you choose to clear them by using the trash bin Clear tool.

The second icon (a hashed polygon) is the Measure Area tool. When you float your mouse over the map, you will see a prompt: Click to create segments. Hold shift to draw free-hand. Click twice in same location to end. When you click through a few segments, and then double-click to end the polygon shape, it turns white and gives you a total area (in square kilometers). You can create as many measuring polygons as required. To clear, click the trash bin icon.

The last icon (a ruler icon) is the Measure Distance tool. You will be prompted on the map Click to create segments. Hold shift to draw free-hand. Click twice in the same location to end. After clicking through to create a few segments, you can double click to end the line measurements. The line will turn white, and a final distance will be displayed. You can create multiple measurements on the map - the clear it, click the trash bin icon.

Below is an example of using all three tools in the Measuring Tools set together. You can deactivate using any measuring tool by clicking on the icon a second time, which returns the icon to a gray color and deactivates the tool.

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Compare Imagery

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You can compare sets of Planet imagery from different days, months, and quarters side by side.

In the toolbar on the right hand side, you will see the Compare icon at the top of the stack. When you click the Compare icon, the map view changes, and you see a prompt to Drag & Drop Images to Compare.

Click and drag any image from the left pane, and release when on top of the map view. You can see the information box in the top center describes the image that has been added to the map view. Repeat again with a second image from the list in the left pane.

Now you can see two images have been added to the map view, and a slider bar is visible in the middle of the map view. The image on the left side of the slider icon corresponds with the tile description at the top left, and similarly for the image on the right side and the corresponding tile description on the top right.

By clicking on the slider icon and moving the mouse left or right, the map interface changes, and you can compare the two images that have been stacked one atop the other.

The icon in the top middle indicates that you can swap the imagery overlay (so that the bottom image becomes the top image).

To swap the image on the map view with a new image, simply click and drag a new image to the map view, and drop in the proper quadrant to replace the image you don't want to compare anymore.

When comparing imagery, there are two tool icons in the bottom left stack - Slide and Opacity.

Slide

This is the default option selected as you choose the Compare tool. This controls the slider bar allowing you to view two images stacked atop each other.

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Opacity

If you choose the Opacity option, you will see the top left image along with an Opacity slider bar at the bottom of the map view.

As you slide the Opacity bar to the right, the top image will fade, and the features of the bottom image will start to become visible.

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Enhance Basemaps

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You can enhance Planet's imagery to adjust for contrast, brightness, and saturation. Enhancements currently work with our basemap imagery product, and work best with surface reflectance basemaps.

Please note: If you have the enhance function on, you cannot apply visualizations. You can turn enhancement on and off by toggling the Off button on and on. If your preset is on, your imagery will continue to be enhanced as you pan and zoom around the map.

To enhance imagery, you can choose from pre-set filters or adjust more granularly to your own liking.

Preset modes include: Basic enhancement: recommended for most use cases Snow: recommended for icy and snowy areas that are typically washed out * Desert: recommended for desert areas that are typically washed out

Custom enhancement filters allow you to adjust for contrast, brightness, and saturation. Adjust by moving the slider to the right or the left.

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Apply Visualizations to Basemaps

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If you would like advanced tools to analyze the imagery beyond the Red-Blue-Green spectrum, you can use the visualization tools.

The visualization tools are located in the toolbar on the right hand side. When you click on the third icon in the toolbar, you will see a menu of visualizations to choose from.

Note: If you are not currently viewing a Surface Reflectance Basemap, you will see a notification that prompts you to switch to a Surface Reflectance Basemap. If your organization has purchased access to multiple Surface Reflectance Basemaps, you will see a list view. If your organization has not purchased any Surface Reflectance Basemaps, you will have the option to view a demo Surface Reflectance Basemap. You can also purchase a Surface Reflectance basemap online with your credit card by clicking Purchase.

The menu of visualizations includes:

  • RGB: Red Green Blue
  • CIR: Color-infrared
  • NDVI: Normalized Difference Vegetation Index
  • NDWI: Normalized Difference Water Index (please note that Planet calculates NDWI using NIR rather than SWIR)
  • VARI: Visible Atmospherically Resistant Index
  • MSAVI2: Modified Soil Adjusted Vegetation Index
  • MTVI2: Modified Triangular Vegetation Index

Changing your color ramp:

If you click CIR, your basemap visualization will change automatically to be color infrared. If you click NDVI, NDWI, VARI, MSAVI2, or MTVI2 you will have the option to select your color ramp in a pop-up in the bottom left-hand corner. Click the edit tool in the upper right hand corner of the pop-up. Click the carrot indicator to view your options. Once you have selected a color ramp, you can save your preferences by clicking “Save”. Your imagery will then reflect the color ramp you chose.

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Enhance & Apply Visualizations to Daily Scenes - BETA

If you would like to enhance contrast or apply visualizations to imagery on a daily cadence, you will have to order an image with surface reflectance capabilities. To turn this capability on, go to the Settings section in the lower left hand corner, and click into the Labs section. Click the toggle next to Enable Folders to turn this beta feature on.

Please note: when you order a scene for analysis in the browser, quota charges will apply. We will create the image with surface reflectance capabilities, store it and host it for one year. Once you order these images, they will be hosted for you in a folder, in "My Hosted Data".

Try tools with Demo Data

If you are not ready to order a scene, you can try out the tools with Planet's demo data. To try demo data, go to the left hand navigation and click on the third icon down. The tooltip reads Access your hosted data for analysis.

Once you click on the icon, you will see a fly out with the option to choose My Folders and Demo Data. Click on Demo Data to see a list of Folders. Folders are organized by examples relevant to industry and geographic areas. Once you find a Folder that sounds interesting to you, click on the Folder to view the imagery in the Folder. Click on the image and go to the tools in the right-hand toolbar to apply visualizations or enhancements.

Order a Scene for Analysis in Explorer

To order a scene for analysis, search for imagery according to your needs, and click Order Scenes. You will see a dialogue box that asks you to choose between ordering for download or ordering for analysis in Explorer.

Please Note: If you would like to order your image for analysis in Explorer and downlaod after, you will have to place two separate orders.

Please Note: Currently, you can only order PlanetScope 4band, PS Orthotile, and RapidEye Orthotile imagery for analysis in Explorer.

Click on the option "I want to order this data for hosted analysis in Explorer" Add your imagery into a Folder. You will see a drop-down of existing Folders with the option to add a new Folder. We recommend naming Folders according to location and adding imagery into a Folder with imagery in a similar AOI.

Once you've selected a Folder, click Place Order. Images can take ~15 minutes to be prepared. Once they are ready, they will appear in your Folder.

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Find your Scenes in your Folder

To find your Folder, go to the left hand navigation and click on the third icon down. The tooltip reads Access your hosted data for analysis.

Once you click on the icon, you will see a fly out with the option to choose My Folders and Demo Data. Click on My Folders to see a list of your Folders. Click into the Folder you just ordered imagery into. If your imagery is still being prepared, you will see a message that reads "Processing images." In each Folder, you will see a list of the images you ordered, organized by date.

If you cannot find the imagery that you ordered, the order failed. You can go to My Orders (the fourth icon in the left hand toolbar) to check on the status of your imagery. If there is a tag that says "Failed" the order has failed, and you will have to place it once more. If you try to order imagery that we do not support, the order will continue to fail. Imagery includes SkySat, PlanetScope 3band, RapidEye Scenes, Landsat, and Sentinel.

Analyze imagery

Click on the image that you would like to analyze in the Folder. Select tools from the right-hand toolbar, as you would for analyzing basemaps.

Using Demo Data

If you would like to try the enhancement and visualizations tools before ordering the scenes for your AOI, you can try out Planet's demo data.

Create a Timelapse

If you would like to compare multiple images over time, you can create a timelapse in the Stories application.

Click on the Stories icon in the right hand toolbar, at the bottom of the stack. When you click on this icon, you will see a pop-up with a link button to take you to the Planet Stories application. In Stories, you can make timelapses of multiple images. You can also publish your timelapses on Planet's website or on your own website or social media account.

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